astroengine writes "On Monday, at around 2 p.m. ET, a coronal mass ejection (CME) slammed into the Earth's magnetosphere. For a short time (between 3:06 p.m and 3:11 p.m. ET), energetic solar wind particles penetrated as deep as geosynchronous orbit — home to hundreds of communication satellites. As a consequence, a geomagnetic storm is underway, generating bright aurorae across very low latitudes." Adds reader dtmos, quoting from Spaceweather, which also has a beautiful photo gallery: "'The impact strongly compressed Earth's magnetic field, directly exposing geosynchronous satellites to solar wind plasma, and sparked an intense geomagnetic storm. As night fell over North America, auroras spilled across the Canadian border into the contiguous United States.' Aurora were seen as far south as Baileyton, Alabama."